A conventional user broadband access line is generally in a manner of digital subscriber line (DSL), which is characterized with narrow line bandwidth and a long distance from a user to a central office. With emergence of new services and expansion of user service scale, a user needs higher bandwidth, but the bandwidth provided in a manner of conventional access cannot satisfy needs of the user.
In a process of researching and practicing the prior art, the inventor of the present invention finds that: due to bandwidth limitation, on the premise of original line characteristics, higher bandwidth and transmission performance cannot be provided for the user, and some services (such as high definition Video On Demand) with higher requirements on the transmission performance cannot be provided to the user, which reduces service experience of the user. For example, for one video stream requiring the bandwidth of 6M for playing, an xDSL line can only provide the bandwidth of 4M at most due to limitation of such factors as distance.